Millions of travellers in public transport, especially in journeys of a determined duration, make use of the time to sleep reclining their head on the seat rest. The shape of this latter only allows the back part of the head to be supported, because of which, after loosing muscular control during sleep, the head is then subject to abrupt sideways movements, or to sustained positioning in non-anatomic postures. In the best of cases the consequence is usually significant discomfort that prevents adequate sleep, including on occasion producing the appearance of cervical lesions.
Some of these seats have an ergonomic design and have a degree of concavity for accommodating the head and lessen its uncontrolled movement during sleep. Some even have “flaps” incorporated, of variable position, adjustable within a certain range of angle, as the user requires. However, a light non-metallic portable system, of reduced dimensions, that the user can quickly and easily be attached and unattached to a wide range of seat backrests, without altering the configuration of these latter, allowing both its fixing at various heights of the backrest, in order to adapt itself to different user heights, and the control of the opening angle of the side headrests to adapt itself to the ergonomic necessities of the user, does not exist.